Sag Shoe Assembly

The Viscometer Sag Shoe Test (VSST) is a well site and laboratory test that measures the weight material sag tendency of field and lab-prepared drilling fluids under dynamic conditions. The VSST provides an intrinsic fluid property without regard to the conditions under which the fluid has been or will be used. As such, results must be combined with operational factors to correlate results with sag experienced in the field.

The VSST designation is derived from the rotational viscometer used as a mixer and the thermoplastic insert (Sag Shoe) designed to concentrate sagged weight material in the bottom of a viscometer thermocup. Sag tendency is determined by the density increase of samples extracted from the collection well over a 30-minute period at a standard temperature and under a consistent rate of shear.

Weight-material bed pickup can be run as an optional measurement to characterize bed removal by higher shear levels. Results can be used to suggest opportunities for bed removal in the field prior to tripping out of the hole.

Part Number

• #130-22